Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) narrates: I was going with the Prophet (peace and blessings be upon him) to the market of al-Naqi'. The Prophet (peace and blessings be upon him) put his blessed hand into a sack, and he brought out grain of mixed kinds (the narrator is unsure; perhaps the words are:) he brought out adulterated grain. So the Prophet (peace and blessings be upon him) said: "He is not one of us who deceives us."
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat; its chain contains a narrator, Yahya bin Uqbah bin Abi al-Ghayzar, and according to one view he used to fabricate hadith.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6343